Asus M3N78 SE - Manual (Page 18)

1-8 Chapter 1: Product introduction
7. Connect the CPU fan cable to the CPU_FAN connector on the motherboard.
Do not forget to connect the CPU fan connector! Hardware monitoring errors can occur if
you fail to plug this connector.
CPU_FAN
CPU
FA
N PWM
CPU F
AN IN
CPU
FA
N PWR
GND
M3N78 SE
M3N78 SE CPU fan connector
5. When the CPU is in place, push down the
socket lever to secure the CPU. The lever
clicks on the side tab to indicate that it is
locked.
6. Install a CPU heatsink and fan following
the instructions that came with the heatsink
package.